Adding new pages to the Wiki is easy.

Create a link on a page to your to-be-created page by placing a Pascal Cased word. When you have saved the page, you will see that the text has a dashed line underneath it. The dashed line under a Pascal Cased word means that page referenced by that link has yet to be defined. Click on the link, and it will allow you to edit your new page.

There's another way to do it that may not be as obvious, but doesn't require you to edit an existing page. On an existing Wiki page, click on the large blue title at the top. You'll see a message: "Enter a topic name to show or a new topic name to create; then press Enter." Type the title of your new page (as a Pascal Cased word) and press Enter. If the page already exists, you will simply be taken to it. If it truly is a new page, then you will be immediately taken to the editor for the new page.

It is important to note that when you create a new page this way, it won't be linked from anywhere else. You will still need to add a link to the page from somewhere else if you expect people to find it. You can find a list of un-linked pages by clicking on "Lost and Found" at the top left.

One more way: just request the URL of the page you want to create. If the path to your home page is http://www.yoursite.com/default.aspx/Topic.HomePage and you want to create a topic called SomeTopicOfMine, just request the URL http://www.yoursite.com/default.aspx/Namespace.SomeTopicOfMine

If the namespace for your new page is the default namespace for your site, you could even omit the "Namespace." part in the URL above.